More than 6,500 police officers have launched a major offensive against prostitution in a hardscrabble manufacturing hub known as China’s Sin City.

Sixty-seven people were arrested during weekend raids on more than 300 addresses in Guangdong province’s Dongguan, including brothels, karaoke clubs, saunas, massage parlours and luxury hotels, state television reported.

China’s “capital of sex” had been placed “under siege,” declared Xinhua, the country’s official news agency.

On Sunday, Hu Chunhua, a rising Communist Party star who became Guangdong’s party chief in 2012, called for a “thorough investigation and crackdown” on sleaze, according to the local media.

Authorities should “locate and cure the symptoms first, [by] making a big noise, and then find and treat the root [cause],” added Hu, who has been tipped as a potential future leader and is a protégé of Hu Jintao, the former president.

The Guangzhou Daily newspaper said Communist Party leaders held an “emergency meeting” immediately after the CCTV expose, which first aired at around noon on Sunday.

By 1pm the first in series of anti-vice raids was underway as police swept into the Ding’an Holiday Hotel and carted off 10 suspects, including the manager.

The operations, which in some cases involved special forces SWAT teams, continued throughout the afternoon, evening and into the night, according to the New Express newspaper.

By Monday morning, 67 people had reportedly been arrested, 12 illegal venues closed and two senior police chiefs had been suspended.

A photograph published by local media showed a naked man using his hands to shield his face from the cameras, as he sat on a pink floral sheet next to a semi-clothed sex worker. On his left hand was a golden wedding ring.

Another image showed dozens of black-clad police operatives crowding around a group of young men and women who were crouching on the floor of a hotel lobby with their hands raised over their heads.

China National Radio claimed one of the hotels targeted belonged to Liang Yaohui, a local multi-millionaire who last year served as a delegate to China’s National People's Congress and was worth around $320m in 2012, according to the Hurun rich list.

The “world’s oldest profession” was banned by the Communist Party following its takeover in 1949 but while prostitution is still technically illegal the sex trade has experienced a major boom since economic reforms were introduced in the 1970s.

Factory cities such as Dongguan, Shenzhen and Foshan have become particularly notorious for the scale of their sex industry.

In a statement, Guangdong’s public security ministry vowed to attack the sex trade with “an iron fist” and to investigate claims that police had provided a “protective umbrella” to local gangs. It thanked the Chinese media for helping authorities “supervise” the illegal industry.

Li Yinhe, a leading sociologist who is known as China’s “first sexologist”, predicted the latest crackdown would have “no effect at all” and said such operations were, in fact, “quite ridiculous.”

Sporadic raids were like “treating the head when the head aches [or] the foot when the foot hurts,” said Prof Li, who is from the Chinese Academy of Social Sciences. “[They] won’t achieve anything or solve any problems.”

China’s out of date and ineffective laws on prostitution needed a radical overhaul and called on the government to decriminalise the sex industry, Prof Li added.

“If we want to reduce the number [of people] in the sex trade… [we must] create job opportunities for the sex workers in other industries and set up vocational training so sex workers can learn professional skills.”